<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>canvas.demo</title>
  <style>
    html,body{
      margin: 0;
      padding: 0;
    }
    .title{
      text-align: center;
      font-size: 24px;
      font-weight: 600;
    }
    .content{
      width: 800px;
      height: 500px;
      border: 1px solid #c3c3c3;
      margin: 0 auto;
    }
    .tools{
      width: 800px;
      margin: 0 auto;
    }
  </style>
</head>
<body>
  <p class="title">塔吊</p>
  <div id="towerCrane" class="content"></div>
</body>
</html>